HTTP Status Codes Error 429: Too Many Requests

Identify: does your log match?

HTTP/1.1 429 Too Many Requests
Retry-After: 30
RateLimit-Limit: 100
RateLimit-Remaining: 0
RateLimit-Reset: 30
Content-Type: application/json

{"error":"rate_limited","message":"Rate limit exceeded: 100 requests per 60s"}

1. High

   Unbounded parallel requests

   Promise.all over hundreds of items or several workers sharing one API key exceed the per-key quota instantly.

2. Medium

   Retry storm after an outage

   Clients retry failed calls immediately and in sync, multiplying traffic right when the server recovers.

3. Low

   Shared IP quota

   Rate limits keyed on IP count all users behind a NAT or a serverless platform's egress as one client.

Fix

while (true) {
  const res = await fetch(url);
  if (res.status !== 429) break;
}

for (let attempt = 0; attempt < 6; attempt++) {
  const res = await fetch(url);
  if (res.status !== 429) return res;
  const ra = Number(res.headers.get('retry-after'));
  const base = Number.isFinite(ra) && ra > 0 ? ra * 1000 : 500 * 2 ** attempt;
  await new Promise(r => setTimeout(r, base + Math.random() * base * 0.2));
}
throw new Error('rate limited after 6 attempts');

Verify: reproduce it on purpose

$ curl -i https://httpbin.org/status/429

Prevent

• Read RateLimit-Remaining and slow down before hitting 0.
• Use a queue with fixed concurrency for bulk jobs.
• Cache GET responses you request repeatedly.